1. Field of the Invention
The present invention relates to tubular members such as production tubing, production casing, or drill pipe, including other types of threaded pipe. More particularly, the present invention relates to a system for cleaning the pin and box ends of threaded tubular members by the use of a high-pressure fluid spray and collecting and filtering the fluid residue. Further, the system allows the separation of the solid components from the residue, so that the solids and filtered fluid are disposed of in an environmentally safe manner.
2. General Background
In the field of threaded connections of pipe, such as drill pipe and production casing, or the like, tubular members are formed into a "string" by the threaded connection between sections of pipe. Normally, as with drill pipe and casing, there is formed a threaded joint between a pin end of a first pipe section, where the threads are exposed on the outer wall of the end of the tubular member, and the box end of the adjoining member, where the threads are formed on the inner wall of the end of the casing. Although the threads are milled to very close tolerances, it is required, in order to insure a connection which will seal properly, that a fluid, often containing heavy metals, such as lead, be placed on the threads, so that the connection, when completed is leakproof. In addition, the threads of the adjoining sections of the tubular members often become coated with the fluids which are pumped down the borehole, for example, during production of a well, or during drilling, which likewise contain heavy solids due to the nature of the fluid.
It is imperative that following the retrieval of the "string" from the hole, and the disconnecting of each section of pipe, that prior to placing the sections of pipe back into operation, that both the box and pin ends of each pipe section be carefully cleaned to insure that no residue remains from the previous use that the pipe had been put to.
At the present time, governmental regulations require that when the ends of the pipe are cleaned, and there may result in a fluid residue containing the heavy solids which coated the ends of the pipe section, that the residue be recovered in such a manner so that the surrounding environment, such as ground and water, not be contaminated with the residue. Therefore, for example, if the cleaning of the tubular members takes place in a storage area, where the pipe members may be placed on pipe racks, if any cleaning of the ends of the pipe members take place, then any fluid which is utilized in the cleaning, must be recovered, since it cannot be allowed to fall onto the ground or run into nearby water sources.
Oftentimes, in the present state of the art, in an effort to capture the fluid residue, absorption mats are placed beneath the pipe end, so that any fluid which runs from the pipe end will fall onto the mat and be absorbed into the mat. The mats are then collected and disposed of. However, quite often, the sections of pipe are placed on the pipe racks in such a manner that the distal end of the pipe, i.e., that end not being cleaned, is lower than the end being cleaned. Therefore, any fluid which would flow into the pipe bore, would naturally run through the length of the pipe, and would flow out of the distal end onto the ground below. It is therefore necessary, that a system be developed which will capture all of the residual fluid which may result from the cleaning process, and prevent any flow of fluid beyond the pipe end being cleaned.
Although that solves one problem, another problem becomes the disposal of the residual fluid, containing the heavy metals, which is accumulated from the cleaning of numerous sections of pipe. Under current regulations, this fluid cannot simply be dumped into a fluid "pit" since such pits are no longer authorized to be contaminated with heavy metal to prevent contamination of local drinking water sources. Therefore, the fluid should be hauled off and disposed of at a distant, authorized site. That process then requires that the fluid be transported via public roads which again may create a hazard should an accident occur during transit. There, there becomes a need to properly dispose of the contaminated fluid on site, so that these hazards are avoided.
A search of the art resulted in the retrieval of several references which are pertinent and which have been made of record in the accompanying Statement of the Art.